A fast chemical-shift imaging using the gradient-echo technique is proposed for the separation of the water and fat in human in vivo imaging. This technique also incorporates magnetic field inhomogeneity correction in the fast chemical-shift imaging. Experimental results of the proposed imaging technique demonstrate that the method would be useful for quick in vivo water-fat separation imaging ...

MR susceptometry-based blood oximetry relies on phase mapping to measure the difference in magnetic susceptibility between intravascular blood and surrounding tissue. The main source of error in MR susceptometry is the static field inhomogeneity caused by an interface between air and tissue or between adjacent tissue types. High-pass filtering has previously been used in conjunction with shimmi...

Brain MRI segmentation remains a challenging problem in spite of numerous existing techniques. To overcome the inherent difficulties associated with this segmentation problem, we present a new method of information integration in a graph based framework. In addition to image intensity, tissue priors and local boundary information are integrated into the edge weight metrics in the graph. Further...

Echo-planar imaging (EPI) is very sensitive to patient-induced field inhomogeneity caused by susceptibility changes between different anatomical regions. This results in geometric and intensity distortions in the image, especially near tissue/air and tissue/bone interfaces. A new approach is presented to reduce geometric and intensity distortions in EPI. A phase-encoded multireference scan is u...

We study the effects of adding a local perturbation in a pattern forming system, taking as an example the Ginzburg-Landau equation with a small localized inhomogeneity in two dimensions. Measuring the response through the linearization at a periodic pattern, one finds an unbounded linear operator that is not Fredholm due to continuous spectrum in typical translation invariant or weighted spaces...

recent developments in nanostructured products draw considerable attention to ultrafine grained materials. these materials are normally manufactured by different severe plastic deformation (spd) methods. in the present study, analytical models and finite element method (fem) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ecap). in additio...

In spite of a huge body of work in medical image registration, there seems to be very little effort in Field of View (FOV) correction or anatomical overlap estimation especially for multi-modal studies. This is a key step for most registration algorithms to work on image volumes of different coverages. In this work, we consider the FOV correction problem between Computed Tomography (CT) and Mag...

Introduction Acquisition of a set Diffusion Weighted Images (DWIs) allows Diffusion Tensors and Tensor-derived quantities such as Fractional Anisotropy (FA) and Trace (TR) to be computed and used to infer the underlying white matter structure in the brain. DWIs are usually acquired with an echo-planar imaging (EPI) pulse sequence that produces images degraded by B0 field inhomogeneity, eddy cur...

For image analysis techniques to be of utility in medical diagnosis systems it is necessary to be able to perform quality control over the results they produce. Input data must conform to the assumptions within the algorithm if useful results are to be achieved. Automation of this process is essential if vision algorithms are to form components in analysis systems. In this paper we present a te...

This work presents a new algorithm (NIC; Non-uniform Intensity Correction) for the correction of intensity inhomogeneities in magnetic resonance images. The algorithm has been validated by means of realistic phantom images and a set of 24 real images. Evaluation using previously proposed phantom images for inhomogeneity correction algorithms allowed us to obtain results fully comparable to the ...